Electric bell.



E. P. STEEN.

ELHOTRIG BELL.

Arrmou'lox Hmm In 19. 1905.

Patented Jan. 5, 1909.

' a manu-snm' 1.

E. P. STEEN.

ELECTRIC BELL.

PPLIGATION FILED MAY 19,1905.

908,899. Patented .1311.5, 1909.

B SHEETS-SHEET 2.

nuzn tot mm dumm,

E. P. STEEN.

ELECTRIC BELL.

PPLmATIox rum) nu 19. 1905.

908,899. Patented Jan 5, 1909.

3 SHEETS-SHEET 3.

:luwuloc UNITED srarns harm onirica.

EDGAR r. s'rnEN, '0F CRIPYIJE cnignjilr,V comme.

IIEEGPIBLIG Application lo Hay 19,

To all whom 'it mwyconcern.

Be it known that I, Enom P. STEEN'l a citizenof the United States, resid' .at Cripple Creek, in the county of Teller an State of Colorado, have invented new and useful Improvements in Electric Bells, of which the ollowing is a s ecication.

The object o my invention is to provide an im roved sin le stroke electric bell particulary adapte to be used in connection with an alternating current light and power circuit, although it may be used on a direct current circuit.

It is further the ob'ect of my invention t0 provide such a bell w ich will be ada ted to avoid excessive sustained currents t rough the magnet coil and in which injurious eddyeurrents may be avoided.

I-hese objects and 'athens will be made-apparent in the followingspecification and claims.

Referring to the drawings-Figure l is a front elevation of my improved bell. Fig. 2 is a side elevation thereof. Fig. 3 is a front elevation showing the magnet coil in section. Fig. 4 isa section taken at right angles to that of F ig. 3. ll ig. 5 isa perspective view of the 4magnet yoke. Fig. 6 rsa pers tive view of the movable magnet core. ig. 7 is a per.- spective view of a modification of my inventlon, and Fig. 48 is a. horizontal. section of the same taken through the magnet coil.

On the base 1, which is made of any suitable material and is adapted to be placed against. a vertical wall, thegong v2 is mounted by means of an extension arm 3. Also attached to this base is a yoke 4 which is made of magnetic metal and has its ends slitted, as indicated by the reference numeral A5. Between the ends ofthe yoke 4 a spool 6 of nonmagnetic non-conducting material is inserted and this s ool is wound with a coil 7, the two ends of W ich are led to the two binding posts 8 mounted on the base 1. The spoo 7 has an axial openingi the walls of which are extended downwar y to form the depending tube 9. The lower end of this tu e 9 is closed by a cap 10 within which is a cushion 11 of some resilient material. Within the tube 9' is a core 12 of ma letic material with corri1 ations 13 extend down its sides. A hig resistance mem bridged across the two binding posts 8, its ends being engaged b the clamps 15 which extend under the bin ing posts. Instead of Sp'eeincaiion ot Letters Patent.

r 14 is- Patented Jui. 5, 1909.

1905. Serial lo. 281,240.

member 14 I may employ a plurality of superposed bars of soft iron depending tube wir holds the magnet cone is closed at its lower end by a cap 19 which carries a thumb-screw 18 project: within, and thus permittin adiustment of t eheight of the base on w the said core rests. th'm modilication I have shown a lam-p at the right of the m t sct'mg as a bridge 'across the te mv: f the cdre. 'like lamp at the top of Fig. V iis intended te be in series with a 'current supply 'ereutindepeudently 'of the cont-aol swatch.

It will d that this bell has no automatic make and break device as 'it is intended to give a single stroke 'on the gong Whenever an operating switch in circuit therewith is closed. The n ic circuit of the coil 7 (reerrim to me' 4 cation of Figs. 1 to 6) -is through t yoke 4 and Aacross the gap between the ends of the {oke from the center of the When the Aell is 'not ener ed the core l2 stands in the depending, tu 9, but with the `rst m of current throu h theeeil 'uponclosum of the control switc the core .1,2 is drawn eneogeticall' upward to close -the ga across the ends o the yoke 4 Aand thus reduce the rehictanoe of the magnetic circuit that has just been referred to. In this u' ward movement of the core 12 it strikes a ard blow en the gong 2 and thus gives-a sngleloud ring. Thereafter the core 12 remains upheld within the coil 7 as lon as thecurrent continues to flow through sai coll.

It will be observed that the description of the operation given thus far applies sobstantially as well whether the bell be energized by a direct current or by an alternating cument and that the bell will work well on either kind of a circuit. -But there are certain features 'in my invention which are especially appropriate to use with an alternating current, and I shall proceed to refer to these. The alternating flux in the magnetic circuit of the bell would have a tendency to produce wasteful eddy-currents in the oles of the yoke 4, hence these poles have een slitted, as indicated by the reference numeral as indicated by dotted lowing respects: The yoke 16 is composed of' from which the polblpieces 17 proiect. The

5 so as to reduce the eddy-currents in a manner well understood in the art. Similarly, eddy-currents would tend to be maintained around the core or plunger 12 and therefore this is grooved longitudinally to minimize the eii'ect. I have not described how to adapt the winding of the coil 7 to a particular voltage, as this is well understood y those skilled in the art. However itis desirable to have the coil so constructed that the alternating current shall flow therethrough in considerable uantity when iirst turned on in order that t e core 12 may be actively energized. The inductive reactance of the coil 7 is therefore made moderate with respect to the frequency of the applied source of electro-motive force, when the core is down in the tube 9. But if the operating switch should be held closed for some time it is desirable that the current in the coil 7 should be choked somewhat so as to prevent useless waste thereof and also to revent overheating the coil. Therefore, t 1e construction is such that when the core 12 is drawn u the inductance of the coil is much increase because of the decreased reluctance of the magnetic circuit. Thus after the iirstrush of current that impels the core 12 against the gong, the current is much abated.

The operation of the modification of Figs. 7 and 8 is substantially the sameas that just described. The lamp bridged across the coil terminals serves a double purpose, (1) it ashes when the gong .strikes and thus combines a visible with an audible signal, and (2) it acts as a discharge `resistance to protect the controlling switch terminals from injury due to the inductive kick ofthe coil 7.

It will be robserved that I have provided a simple, durable and effective bell which can be used on ordinary power circuits and is economical in its consumption of current.

1. An electric bell 4com rising a go a coil, and an iron core for e coiladapte to act as a hammer for the gong,'the parts being so constructed that the magnetic circuit of the coil shall have a large air ga when the core is withdrawn fromtli'e "co' but shall have a very small air gap when the core is Within the coil.

2. An electric bell com rising a gong, a coil, an iron yoke outside t e coil and having its ends overlapping the respective ends'of the coil, an iron core for the coil adapted to act as a hammer for the gong and when within the coil to substantially complete' the magnetic circuit of the said yoke. A

3. An electric bell com rising a gong, a coil, an iron yoke outside th its ends slitted and overlapping the respective ends of the coil, an iron core for the coil adapted to act as a hammer forthe gong and when within the coil to substantially complete the magnetic circuit of the said yoke.

4. An electric bell comprising a gong, a coil, a longitudinally grooved iron core for the coil adapted -to act as a hammer for the gong, the arts being so constructed that the coil shall have a moderate inductance when the core is withdrawn therefrom, but shall have a relatively high inductance when the core is within the coil.

5. An electric bell comprising a gong, a

coil, an`iron core for the coil adapted to act as a hammer for the gong, and a lamp in parallel with the coil, the parts being so constructed that the magnetic circuit of the coil shall lhave a large air gap when the core is withdrawn from the coil, but shall have a very small air gap when the core is within the coil.

6. An electric bell comprising a gong, a coil under the gong having its axis vertical, a core adapted to move up within the coil and a tube extending down from the coil adapted to hold the core with its upper end in proximity to the coil when it is not energized by current.

'7..An electric bell comprising a gong, a spool'of non-conducting non-magnetic material, a coil wound thereon, a oke having its ends embracing the ends of said spool, and a core adapted' to act as a hammer for the bell and to complete the magnetic circuit of the yoke within the spool.

8. An electric bell comprising a gong, a coil, a' yoke forming a artial magnetic circuit for the coil, a mcvab e core adapted in one vposition to complete said circuit, the reluctance of said magnetic circuit being much less and the impedance of the coil with respect to alternating currents being much greaterwhen the core completes the magne'tic circuit than when it does not do so.

In testimon whereof, 1 aiiix my signature inpresence o two witnesses.

EDGAR P. STEEN.

Witnesses:

HAzEL B. RHODES, J. H. ScmssLER.

e coil and having 

